LIST OF ILLUSTRATIONS XXV 



Page 



297. Tumor-bearing olive branches from Genoa, Italy 390 



298. Olive tubercles due to Bacterium savastanoi EFS — pure culture in- 



oculations of 1903. Washington, D. C 391 



299. Olive branch showing dwarfing and death of terminal (inoculated) 



shoot and new surface infections below 391 



300. Young olive tree showing result of inoculating Bacterium savastanoi 



(at X) 392 



301. A detail from figure 300, about ^4 natural size 393 



302. Cross-section of a young cheesy olive tubercle, slightly magnified 393 



303. Like figure 302 but more highly magnified 395 



304. Channel of infection (X) in an olive petiole. Low power 396 



305. A detail from figure 304 at X, showing the bacteria. Highly magnified 397 



306. Cross-section of an olive twig at the level of a small tubercle which is 



composed chiefly of bark-cell proliferations 398 



307. Section of small tubercle on under surface of an olive leaf 399 



308. Luigi Savastano. Photograph made in Naples at time he was studying 



olive tubercle (1897 to 1899) 400 



309. Flagellate rods of Bacterium savastanoi 401 



310. Agar surface and buried colonies of Bacterium savastanoi 402 



311. Surface colony of Bacterium savastanoi on gelatin 37 days. Year 1908. 



Enlarged 403 



312. Gelatin surface and buried colonies of Bacterium savastanoi. Year 1910. 



Enlarged 405 



313. Ringed surface colony of Bacterium savastanoi on + 10 peptone beef 



gelatin with 1 per cent dextrose. Enlarged 407 



314. Agar-poured plate of Bacterium savastanoi, Vi insolated (on ice) 30 



minutes with killing effect 408 



315. Inoculated crown gall on hop due to Bacterium tumefaciens Smith and 



Townsend 413 



316. Dwarfing effect of crown-gall on sugar-beet — inoculated 37 days 414 



317. 1. Crown gall on hop — Washington State. 2. Crown gall on rose — 



New Jersey. 3. Crown gall on apple limb — North Carolina. 4. 

 Grafted crown gall on a pear seedling — Washington, D. C 415 



318. 1. Inoculated crown gall on yellow Paris daisy— 1 month la. Inoculated 



crown gall on yellow Paris daisy: one infected needle-prick; sterile 

 pricks above. 2. Inoculated crown gall on peach — time, 5 months. 

 2a. Ditto, time 18 days, 1907. 3. Inoculated crown gall on apple stem. 

 4. Inoculated crown gall on grape. Time, 44 days 416 



319. 1. Inoculated crown gall on radish. 2. Paris daisy showing primary 



(inoculated) stem-tumor (at X); and 3 secondary (leaf) tumors — 

 73 days. 3. Crown gall on Paris daisy, time 10 months. A new 

 tumor developed below the sloughed old one. Stem dead. 4. 

 Secondary crown gall on sunflower due to proliferation from a tumor- 

 strand, primary tumor in the disk. 1915 5. Crown gall on Paris 

 daisy. Section of stem between tumors showing a large tumor- 

 strand. 6. Crown gall on Paris daisy. Section of stem between 

 tumors showing 3 tumor-strands; also secondary tumors growing 

 out of the leaf stubs 418 



320. Crown gall on sugar beet — inoculated 3 months. Tissues sound 420 



